Submarine MOC Blueprint Guide: Hull, Periscope and Propeller

Submarines are the understated branch of the military brick hobby. There is no carrier deck crowded with fighters to distract the eye, only a clean hull curve, a sail (conning tower) and that one unmistakable periscope. Because the shape is so simple, a submarine MOC exposes your structural fundamentals faster than almost any other subject. Get it right and it reads instantly as a predator under water; get it sloppy and you have a tube stuffed with bricks.

This guide walks through a brick submarine MOC blueprint from picking the file to the final detail, covering the points that actually decide whether the model looks right.

1. Choosing a blueprint: three things to check first

Before you start ordering parts for a submarine MOC blueprint, verify these three points:

• Scale and finished size. A good blueprint lists the completed length (1:500 and 1:350 are common). For a desk display, anything under 30 cm is plenty. The finer the scale, the higher the part count, so set a budget before you commit.
• Internal structure. A serious blueprint explains how the hull skeleton goes together and where the ballast sits. If it only shows exterior renders, you will likely end up with a solid brick lump.
• Parts list. Only a complete list with part numbers, colors and quantities saves you headaches. Otherwise you stall halfway through, waiting on a missing order.

2. The hull: building round, then closing it in steps

The hull is the skeleton of the whole model. Two words matter: round and smooth.

Building a cylinder. Pure stud-up stacking will never look circular. The practical answer is side building (SNOT): use 1x1 bricks with a stud on the side and 1xN plates to lay the surface flat, then clad the outside with curved plates or slope bricks to create a continuous curve. At small and medium scales, wrap 2x6 plates around the axis with staggered joints to form a polygonal cross-section, then skin it with curved elements. Visually it reads perfectly round.

Tapering in steps. The bow and stern must not end in a flat cut. Each ring should pull in one or two studs compared with the one before it, with wedge bricks and slope bricks closing the gaps, and curved pieces bringing the tip to a point. Leave an opening at the stern for the propeller shaft. Always stagger the joints in the tapering sections, or you will see a row of vertical seams down the flank.

3. The sail and conning tower

The sail is the most recognizable feature of a submarine, and it decides whether the model reads correctly.

• Keep the sail a long, slim teardrop with flat left and right faces. Stack it from 2x6 and 2x8 plates, and narrow the top slightly toward the front for a more modern silhouette.
• The interior can stay hollow, or you can build a cutaway bridge with transparent pieces as windows. That is a strong bonus on the display shelf.
• The joint between sail and hull is where models most often float in mid-air. Run Technic beams lengthwise inside as support and add several connection points along the bottom, rather than hanging the whole thing on two studs. Many blueprints make the sail a removable module so you can show the interior, which is worth looking for when you choose a file.

4. Periscope and propeller: making the moving parts move

These two working details show how much thought went into the build.

• Periscope. Run a thin Technic axle through the top of the sail and cap it with a cylinder piece as the periscope head; turn the axle and the head rotates. Add a turntable or hinge element and you can also mimic the raise-and-tilt motion. Avoid fragile thin rods, and if the sail stands four or five bricks tall, fit an axle sleeve partway up for reinforcement.
• Propeller. Ready-made blade elements with a cross axle and an axle connector give you a propeller you can spin by hand. The shaft must pass through the stern and anchor to the internal frame; only then does it turn steadily. Build the stern planes and bow planes from hinge pieces so they stay adjustable, which makes diving and cruising poses look far more natural. Size the control surfaces to the beam of the hull and resist the urge to oversize them.

5. Ballast and common pitfalls

The biggest trap in a submarine MOC is not the exterior. It is that the model will not sit still.

• Ballast. A long, narrow hull with a high center of gravity needs weight. Put metal ballast bricks at the lowest point of the internal keel, or wrap a few coins in bricks, so the finished model settles firmly on the display stand.
• A hull that is not round. Skipping wedge bricks in the tapering section leaves visible facets on the curve. Test-fit each layer before you fix it down.
• A wobbly sail. An unsupported overhanging section skews the moment you touch it. Add internal beams.
• Details that snap off. Periscope rods and control surfaces without reinforcement break during handling. If an axle sleeve fits, use it.

Where to find submarine blueprints

Submarines look simple on the box, but getting the hull to close in cleanly, the sail to stand rigid and the periscope to actually turn takes patience and a couple of rebuilds. When you choose a blueprint, remember the three checks: size, internal structure and parts list.

If you want to build one, browse BrickPlans (https://brickplan.cn), which carries military MOC blueprints including submarines and warships. Search for "submarine" or "warship" and you will find files with complete parts lists and step-by-step instructions, ready to build into a model that dominates the desk.